Update certificates to expire in 2029

Update certificates that expire on 2021, to prolong their validity,
to make tests pass three years ahead.
diff --git a/tests/data_files/server2.crt b/tests/data_files/server2.crt
index 33393ee..0745196 100644
--- a/tests/data_files/server2.crt
+++ b/tests/data_files/server2.crt
@@ -1,7 +1,7 @@
 -----BEGIN CERTIFICATE-----
 MIIDNzCCAh+gAwIBAgIBAjANBgkqhkiG9w0BAQUFADA7MQswCQYDVQQGEwJOTDER
 MA8GA1UECgwIUG9sYXJTU0wxGTAXBgNVBAMMEFBvbGFyU1NMIFRlc3QgQ0EwHhcN
-MTEwMjEyMTQ0NDA2WhcNMjEwMjEyMTQ0NDA2WjA0MQswCQYDVQQGEwJOTDERMA8G
+MTkwMjEwMTQ0NDA2WhcNMjkwMjEwMTQ0NDA2WjA0MQswCQYDVQQGEwJOTDERMA8G
 A1UECgwIUG9sYXJTU0wxEjAQBgNVBAMMCWxvY2FsaG9zdDCCASIwDQYJKoZIhvcN
 AQEBBQADggEPADCCAQoCggEBAMFNo93nzR3RBNdJcriZrA545Do8Ss86ExbQWuTN
 owCIp+4ea5anUrSQ7y1yej4kmvy2NKwk9XfgJmSMnLAofaHa6ozmyRyWvP7BBFKz
@@ -10,11 +10,11 @@
 hYvai0Re4hjGYi/HZo36Xdh98yeJKQHFkA4/J/EwyEoO79bex8cna8cFPXrEAjya
 HT4P6DSYW8tzS1KW2BGiLICIaTla0w+w3lkvEcf36hIBMJcCAwEAAaNNMEswCQYD
 VR0TBAIwADAdBgNVHQ4EFgQUpQXoZLjc32APUBJNYKhkr02LQ5MwHwYDVR0jBBgw
-FoAUtFrkpbPe0lL2udWmlQ/rPrzH/f8wDQYJKoZIhvcNAQEFBQADggEBAAFzC0rF
-y6De8WMcdgQrEw3AhBHFjzqnxZw1ene4IBSC7lTw8rBSy3jOWQdPUWn+0y/pCeeF
-kti6sevFdl1hLemGtd4q+T9TKEKGg3ND4ARfB5AUZZ9uEHq8WBkiwus5clGS17Qd
-dS/TOisB59tQruLx1E1bPLtBKyqk4koC5WAULJwfpswGSyWJTpYwIpxcWE3D2tBu
-UB6MZfXZFzWmWEOyKbeoXjXe8GBCGgHLywvYDsGQ36HSGtEsAvR2QaTLSxWYcfk1
-fbDn4jSWkb4yZy1r01UEigFQtONieGwRFaUqEcFJHJvEEGVgh9keaVlOj2vrwf5r
-4mN4lW7gLdenN6g=
+FoAUtFrkpbPe0lL2udWmlQ/rPrzH/f8wDQYJKoZIhvcNAQEFBQADggEBAJklg3Q4
+cB7v7BzsxM/vLyKccO6op0/gZzM4ghuLq2Y32kl0sM6kSNUUmduuq3u/+GmUZN2A
+O/7c+Hw7hDFEIvZk98aBGjCLqn3DmgHIv8ToQ67nellQxx2Uj309PdgjNi/r9HOc
+KNAYPbBcg6MJGWWj2TI6vNaceios/DhOYx5V0j5nfqSJ/pnU0g9Ign2LAhgYpGJE
+iEM9wW7hEMkwmk0h/sqZsrJsGH5YsF/VThSq/JVO1e2mZH2vruyZKJVBq+8tDNYp
+HkK6tSyVYQhzIt3StMJWKMl/o5k2AYz6tSC164+1oG+ML3LWg8XrGKa91H4UOKap
+Awgk0+4m0T25cNs=
 -----END CERTIFICATE-----